Power adapter



FIG. 1 is a top-back-right side perspective view of a power adapter of our design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a back view thereof; and,

FIG. 7 is a left side view thereof. 

CLAIM The ornamental design for a power adapter, substantially as shown and described. 